The present disclosure relates to electronic components and more specifically to temperature monitoring of electronic components.
Fire detection in aircraft utilizes smoke detection and overheat sensors to quickly and efficiently detect fires. Current aircraft regulations require that a system must detect a fire in the cargo compartment and provide visual indication to the crew within one minute. Further, lavatory systems and avionics bay systems conform to specific requirements for those areas. However, fires that are much smaller in size, in critical locations and sometime in confined locations possess a special risk. Early reliable detection would allow for better control of the fire. Higher sensitivity enables earlier detection, but increases the risk of false alarms. Advances in signal processing and sensor design for point sensors and aspirating systems have decreased nuisance alarms by incorporating temperature and smoke detection.
However, over heat and smoke sensors are bulky, limiting their use to larger parts off the airplane, and can be prone to false alarms and be difficult to maintain. Further, such sensors typically require a weight and power budget, and can have difficulty detecting smoke in areas with a high airflow rate. Over heat detectors can be thermistor, eutectic salt and pneumatic elements. The predominant approach utilizes eutectic salts, which is very sensitive and failsafe. However, is prone to vibration, heavy and difficult to maintain during routine aircraft maintenance. New approaches that can reduce the footprint, are vibrationally insensitive and easily maintainable are advantageous. In addition, integrated fire protection technologies that reduce weight, power and foot print are advantageous to the air framer.
Current smoke detection for aircraft electronic components is either accomplished indirectly or not at all. Typical areas that are covered include avionics, E/E bays. Smoke is detected in these areas by sampling the electronics cooling air that is removed from the particular bay. This method of detection can only notify the crew of a fire in that bay, it cannot distinguish one electronic component from another. Automatic discharge fire extinguishers are not used in these areas due to the risk of damaging non-affected equipment. Typical areas that are not covered by smoke detectors include but are not limited to aircraft; cockpits, all cockpit electronics, cockpit glare shields, cabin electronics, remote data collectors etc. The size and weight of current aircraft smoke detectors pose a significant challenge for detecting smoke in the vast array of aircraft electrical systems. Smoke detection in these areas is left to the crew for visual and manual detection techniques.